Apparatus for annealing



March 28, 1944. u w. B. COOPER x-:TAL 2,345,131

APFARA'TUS FOR ANNEALING Filed April 6, 1940 13 Sheets-Sheet 1 IPI Il nl u Il Il ILM K Milizia/n .EL Cooper', .Edward Jeabald.

Mardi 28, 1944 A w.vB. COOPER ET'AL 2,345,181

APPARATUS FOR ANNEALING l vFiled April 6, 1940 15 Sheets-Sheet 2 Wiliam Coqoa. Edward J." J'eaboZaL www March 2s, 1944. 1 w, B COOPER' ETAL 2,345,181

APpARATUs Fon ANNELING Filed April' e, A1940 1s sheets-sheet s ZT/2 4. v

/ y JS@ Wauw Cob/Jen Edward l eabola.

March 2s, 1944. w B, @OPER ETAL. 2,345,181

APPARATUS FOR ANNF'ALING Filed April 6, 1940 15 sheets-Sheet 4 me/wim March 28, 1944. w, B, COOPER [-:1-V AL 2,345,181

A i APPARATUS FOR ANNEALINQ Filed April 6, 1940 15 sheets-Sheet 5 m R1 Syvum/Kolb ki William Cba/nera. Edward l 56mm March l28, 1944.

w. B. COOPER law-Al.A 2,345,181

APPARATUS FOR NNEALING Filed April 6, 1940 A13 Sheets-Sheet 6 Fg. JJ:

u SWW t 134 v Mam COO/Mft.

Edward feabod March 28, 1944. w, B COOPE-R E -r AL 2,345,181

APPARATUS FOR ANNEALING Filed Aprl'G, 1940 l 15 Sheets-Sheet '7 William Cooper' Edward J Jeabald.

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March 28, 1944. w, B, COOPER ET-AL 2,345,181

APPARATUS FOR ANNEALING Mamr 2389 i944., w. B. COOPER ETAL I y i APPARATUFOR ANNEALING' 15 sheets-sheet 9 Filed April 6, 1940 March 28, 1944. w. B. cooPER ETAL v 2,345,181

' lAPPARATUS FO ANNEALING I Filed April e, 1940 1s sheets-sheet 1o WZZL'a/n 52 Coo/Uefa y n Edward feabolc.

March 28, 1944. w. B. coo'PER x-:TAL

APPARATUS FOR ANNEALING 13 Sheets-Sheet ll Filed April '6, 1940 NNN NNN

mwN @MN 13 Sheets-Sheet l2 Filed April 6, 1940 W. B. COOPER EVAL AFPARATUS FOR ANNEALING March 28, 1944.

Patented Mar. 28, 1944 William n. cooper and Edvard J. scatola, Bammore, Md., assignors to Crown Cork Seal Company, Inc., Baltimore, Md., a corporation of New York Application. April 6, 1940, Serial N0. 328,292

3 claims. (Cl. is-zs) i the temperature to which the strip is subjected,

The present invention relates to a method of and apparatus for continuously handling and annealing strip steel.

More particularly, the invention isI concerned -with means for and methods of continuously bright-annealing low carbon, cold rolled strip steel.

It is an object .of the invention to provide an improved continuous annealing method to take the place of conventional batch annealing processes, thereby to improve the quality and uniformity of the anneal, as well as to shorten the annealing time and reduce its cost.

Itis a further object to increase the tonnage of strip steel that may be annealed in a given length of time with an apparatus occupying a particular area of plant space.

Et is a further object of the invention to reduce greatly the cost of annealing strip steel, by materially reducing the heating costs, the handling4 costs and other labor charges.

It is a further object of the invention to ,produce inthe strip steel an improved anneal, characterized by small, uniform grain structure, resulting from the use of high annealing temperatures followed by rapid cooling from the critical temperature yto substantially room temperature. In accordance with theinvention, the material is maintained at a high annealing temperature for a suiiicient period of time to permit the crystallinevgrains to lose the orientation and elongated shape acquired in cold rolling. and to assume the random positions characteristic of well-annealed steel, but the steel is cooled with suillcient speed to prevent the formation of large l grains of ferrite, which is a characteristic result of the long cooling periods used in batch annealins- Itis a further obiect of the invention to 'provide novel, improved means for acc rately and .uniformly controlling the temperat e to which Qthe strip is raised during its treatment, the time "during which the strip is held or soaked at a high temperature, and the time, rate and degree ofcooling. 1

'It is a further object of theinvention to provide novel means for preventing or controlling oxidation of the strip, during the annealing process, whereby a Ibright-annealed strip ora strip having desired, controlled color characteristics, may be produced.

yOlie of the principal objects and advantages of the present invention is the elimination. in a continuous annealing method, of iiuctuations in from the furnace. To this endl the invention l steel from which the whereby inequalities in the ductility and hardness of the annealed strip are eliminated. Thus, the invention includes novel methods of maintaining the 'heating means and the strip passing through particular zones of the furnace at desired constant temperatures.

A further important object of the invention is to provide novel means for maintaining the temperature in the strip, transversely thereof substantially uniform, so as to produce a strip that is uniformly annealed/transversely thereof, characterized by the absence of burned or overlyheated edge portions or insuiliciently heated central portions.

It is a further object of the invention to provide novel methods of controlling the hardness and ductility of the annealed strip, by controlling and varying the temperature in the soaking zone and the cooling rate.

A further object of the invention isfto provide novel means for and methods of handling strip steel and delivering the samev continuously to the annealing furnace, and for handling and reeling the annealed strip as it is discharged contemplates providing a reserve supply of strip ma rial may be continuously delivered to the iu'ace while the trailing end of one supply reel welded to the leading end of the next, so that no interruption in the delivery of strip to the furnace need occur. The invention also may include novel means for cleaning the strip before it is introduced into the furnace. Cold rolled strip steel, as it c mes from the rolling mill, has on its surfaceaw coating of palm oil or thellike which, preferably, is

- removed before introduction of thestrip into the furnace. The invention includes novel means for performing this function continuously as the strip is delivered to the furnace.

A further advantage of the preferred arrangement of strip handling material is that, if desired, the annealing furnacemay be by-passed and the strip drawn through the cleaning apparatus and the reeling machines directly to the reeling device, so that, in the vevent of a shutdown of the furnace for maintenance or repairs,

the cleaning apparatus may be utilized, the strip rolled up into the usual coils and the latter annealed in a batch annealing furnace or the like.

It is a further object to provide, on' the discharge side of the furnace, novelstrip handling instrumentalities whereby, when a predetermined amount of metal has been wound up on an ex- Dansible and contractible mandrel in the form of a reel or coil, the strip may be cut, the coil removed and the winding of a new coil started, ail without interrupting the delivery of strip continuously from the furnace. g

Other objects and advantages of the invention will be apparent from a consideration of the following description of certain speciiic embodiments of the invention shown in the accompanying drawings.

In the drawings:

Figure 1 is a diagrammatic side elevation of one form oi annealing apparatus.

Figure 2 is a diagrammatic plan view of a preferred arrangement of strip handling and treating instrumentalities on the infeed side of the annealing apparatus.

Figure 3 is a diagrammatic side elevation of the same.

Figure 4 is a side elevation of a preferred form of annealing apparatus, with certain parts removed for the sake of clarity.

Figure 5 is a diagrammatic plan view of a preferred arrangement of strip handling instrumentaiities on the delivery side of the annealing apparatus.

Figure 6 is a side elevation of the mechanisms shown in Figure 5.

Figure 7 is a vertical sectional view of the heating section of the annealing furnace of Figure 4, on a somewhat enlarged scale, with certain parts removed and other parts broken away.

Figure 8 is a transverse sectional view taken on line l-I of Figure 7.

Figure 9 is a top plan view of the apparatus of Figure 4, with certain parts removed.

Figure 10 is an enlarged fragmentary vertical section through one of the heating chambers'V showing a preferred arrangement of heating elements.

Figure `11 is a sectional detail, showing a preferred terminal arrangement.

Figure 12 is a vertical sectional view of one of the caps 0r hoods for closing the upper end o! one of the heating chambers.

Figure 13 is a horizontal sectional view showing the furnace door inplan.

Figure 14 is a side view, on an enlarged scale, partly in section and partly in elevation, showing the lower end of the furnace structure and strip guiding means.

Figure 15 is a fragmentary vertical section taken on line II-Il of Figure 14.

Figure 16 is a plan view of the furnace casing, with the brickwork, guiding rolls and closure hoods removed.

Figures 17, 18. 19 and 20 are sectional details, taken on corresponding section lines on Figure 1 Figure 21 is a plan view of a channel-forming frame member or collar adapted to be mounted at the upper ends of the side walls of the fure nace casing.

Figure 22 is an end elevation of the member shown in Figure 21, while Figures 23 and 24 are sections on corresponding section lines on Figures 21, 22.

Figure 25 is a plan view of the hood or cap shown in Figure 12, while Figures 26 and 27 are an elevation and a vertical section, the latter being taken on line 21-21 of Figure 26.

Figure 28 is an end elevation of one type of cooling chute section.

Figure 29 is a side elevation taken from the right of Figure 28, with certain parts removed.

Figure 30 is a side elevation of a water-jacketed cooling chute section.

Figure 31 is an end elevation of the chute section shown in Figure 30.

Figure 32 is a fragmentary end elevation of a modified form of chute.

Figure 33 is a sectional view of a detail, on an enlarged scale.

Figures 34, 35 and 36 are'end and side elevational views of still another type of cooling chute section, while Figure 37 is a bottom plan view thereof.

Figure 38 is a vertical sectional view through a strip discharge assembly adapted to be associated with the last cooling chute section.

Figure 39 is a side elevation of the assembly shown in Figure 38, whilev Figure 40 is an inverted horizontal section taken on line lil-46 of Figure 39.

Figure 41 is an elevational view on an enlarged scale of one of the cooling units adapted to be associated with the chute section shown in Figure 28.

Figure 42 is a transverse section through the apparatus of Figure 4 1.

Figure 43 is a vertical sectional view of a gastight roll seal through which the strip passes to or from the annealing apparatus.

Figures 44 and 45 are side and front elevational views of the apparatus of Figure 43.

Figure 46 is afplan view of a cooling water delivery header and return trough.

Figure 47 is a side elevation of the same, while Figure 48 is a vertical section on lines IIB- 4l oi Figure 47, and

Figure 49 is a circuit diagram of the heating elements in one of the heating sections of the annealing furnace.

In Figure 1, there is shown a diagrammatic view of a simple form of apparatus constructed in accordance with the invention. Strip steel Iii is drawn from any suitable source of supply through a looper Ii, a furnace l2 and a cooling apparatus i3, and then under a delivery roll I4 to a suitable reeling device or the like. As pointed out below, the strip IU may come from theinstrumentalities shown in Figures 2 and 3, and may be delivered from the furnace to the devices shown in Figures 5 and 6, but the invention, in its broadest aspects, is not limited to the use of these particular mechanisms, as equivaplatform I6; upper rollers i1, rotatably carried by a vertically movable frame I8, and supporting cables or the like I9, suitably counterbalanced by means not shown. The strip follows a serpentine path in the looper ii, thereby providing a reserve supply of strip, and then passes around a first guide roll 20, from where it is drawn through a gas-tight, roll seal 2l into the rst heating chamber 22. The seal 2| may be constructed substantially in accordance with the showing in Figures 43-45, described in detail below. An upper furnace roll 2l, disposed in the upper end of the annealing furnace at the point of junction between the vertical chambers 22, 26 guides the strip through the chambers. During its passage through the chambers 22, 25, the strip is subjected to radiations from highly heated electrical heating elements 26, arranged in groups orzones, as described below and continuously maintained in heated condition by suitable control means.

The highly heated strip is drawn downwardly through an opening in the door of the chamber.

25 into a roll housing 21, where itis trained about rolls 28, 29 for delivery to the first cooling chute 30. The several cooling chutes 30-35 are connected at their upper and lower ends by roll housings 3B, 31 having guide rolls 88, 39 therein,

over which the stripis trained for movement and gasketed joints. An oilor oil and sand seal 40 may be provided around the line of junction between theremovable cap 4I for the heating section and the furnace walls, as explained more particularly below in connection with the form of furnace shown in Figure 4. An atmosphere of a non-oxidizing gas is maintained in the in- A terior of the heating and cooling chambers, preferably at a pressure suiiiciently above atmospheric pressure to prevent the Iinadvertent entry of air. Clean fuel gas burned in an insuflicient supply of air will provide an atmosphere which will protect the steel during the annealing operation, ifit is dried sufficiently and burned to a suitable analysis, for instance. CO2 5, 6%; C O l0, 12%; H2 10, 13%; and N2 balance. It is important that the gas be dried before it is introduced into the furnace, so that there is at least twenty' times as much Ha as H2O. A pressure of 0.2 inch water pressure above atmosphere, maintained in the furnace and in the cooling chambers has been found to be sufficient to prevent the entrance of atmospheric air. Any air that does enter the furnace immediately combines by burning with the highly heated hydrocarbon atmosphere therein.

As described below in detail in connection with faces of the strip to effect further cooling of the material.

y Preferably, the sections in the chute 30 are water-jacketed, as shown in Figures 30-32 and described below, while thesections' in chutes 3l-34 are of the type shown in Figures 28 and 29 and may have associated therewith, positive gas circulating and cooling means, described below.

The heating elements 28 preferably are of the type shown more in detail in Figures 8 and 10 and -are connected in banks on opposite sides of the heating chambers in series, as indicated diagrammatically in Figure 49 so that opposite sides cated by controllers CI, C2, etc., in Figure 49. Usually, the two banks of heating elements in each zone, connected in series, receive current from a suitable source of supply Ll, L2, in parallel with the elements in other zones, but it is l often found desirable to connect all of the elements in two or more 4zones together in series.

In any event, in th" operation of the furnace strip having a width of thirty inches and a thickness of .0115, the heating elements are energized with a total constant input of 720 k. w. 'I'he strip travels at substantially 205 feet per minute and remains in the annealing apparatus, including heating and cooling chambers, a period of one minute and forty-live seconds. 'I'he maximum temperature to which the strip is raised is approximately 1625u F., followed by heating at progressively lower temperature to eliminate any transverse inconsistencies in the temperature gradient. The strip leaves the heating chamber at substantially 1400 F. and, by means of the water-jacketed cooling chutes is reduced, in about fteen seconds to a temperature of substantially 1050 F. During the next thirty-live seconds in the subsequent cooling chutes, the temperature is reduced to substantially 275 F. In the nal, aircooled chute or chutes, the temperature is reduced from 275 to 'about 175l F., in a period of twenty-five seconds, whereupon the strip may be safely exposed to atmospheric air without any substantial danger of oxidation or scale formation.

It must be understood that the invention is not limited .to the particular figures given above, as, for diiferent strip speeds, dfiferent temperatures are maintained in the heating and cooling chambers. For instance, the following figures illustrate typical temperature, by zones, fora run of .0115 gauge steel, drawn throughat 210 feet per `:ninute:

1 2 3 v4 5 0 7 8 Temperature F.. 1, 520 1,575 1,610 1,640 1,660 1,700 1,715 1, 740

9 l0 1l l2 14 15 Zone of the strip are subjected to equal heat 'radiations. Each bank may include four rows of loops or festoons in series, and a pair of banks of elements ogn opposite sides of the chamber constitute a heating zone. As indicated in Figure 1,

the furnace comprises sixteen zones, each of' which may be independently controlled, as indi- 13 16 Temperature F.. 1,670 1,635 1,005 1,575 1,545,1,405 1,450 Out The total k. w. input in the above run was '720. The annealed steel tested as follows: Erickson, 860; Olsen, 335; Rockwell, 52B.

The furnace shown in Figure 1 is provided.

with an electrical pyrometer for each vheating zone (consisting of two banks of heating' elements,

one on each side of the strip) and a controlling potentiometer for each group of threev zones.

Hence, the temperature conditions in the furnace may be observed at all times.

An important feature of the present invention is the adjustment of the current input and consumption to the thickness of steel being annealed, .If the current input and the thickness of the strip remain constant, a constant' annealing result will be accomplished, providing the time element (speed of travel of the strip through the furnace) remains constant. Dimculties are encountered if attempts are made to control thetemperature in the furnace by manuallyV varying the now ot current to the heating elements, or by automatically, through a thermostat control, cutting certain of the elements into and out of operation. Wide iiuctuations in the annealing results have been found to follow from such methods, since there is necessarily a very substantial lag in changing the conditions of the heating elements, with the result that, for at least a substantial period oi' time ln the annealing cycle, the elements are either too hot or too co d.

In accordance with the present invention, the current input to the heating elements remains constant for a particular gauge of strip steel, so that there are normally no substantial fluctuations in the temperature of the elements. Compensation for minor variations in the thickness of the strip, for instance, such as may be encountered at the ends of the rolls, is effected by controlling and varying the speed of travel of the strip through the apparatus. That is, when heavier portions of the strip are travelling through the heatingzone, the speed oi' travel is decreased, to enable the thicker m-aterial to absorb a greater amount of heat and to extract, from the heating zone, a number of heat units in a given length of time equivalent to that extracted by the more rapidly moving, thinner strip sections. Conversely, if the strip contains thin portions, its speed of travel is increased somewhat, thereby maintaining the strip and the elements at a substantially constant temperature.

The following table gives typical figures as to width, current input and speed of travel of certain standard gauge strip steel when annealed in the apparatus of Figure 1. Also, figures for Erickson, Olsen and Rockwell tests are given.

width Tls; lfqf'- speed Erickson olsen Rkweu Inches so .noos am 195 soo-eso aoc-32o 53-55 am .oiov 72o 22o soo-seo soo-32o sass ao oo om 21o 82H40 305-325 49-52 so .ons rm aus S40-seo 31o-34o 4s-52 When operating with .0115, thirty inch strip, the output of this furnace is 160 tons per 24 hour period of operation. In actual operation, the annealing cost in connection with this furnace has been reduced 60%, as compared with prior batch annealing methods.

The broad principles of operation and features of construction, described above in connection with the apparatus showndiagrammatically in Figure l, are incorporated in the apparatus of Figure 4, 'together with additional structural rennements, inventions and improvements. The strip handling equipment shown in Figures 2. 3, and 6, as stated above, may be employed with either form of furnace, disclosed in Figures l and 4, or equivalent devices may be employed.

In Figures 2 and 3, two coil supporting devices, represented generally at 4i, 46, deliver strip steel alternately from coils 41, 48 supported thereon. The strip passes through a .welding machine 50, a tension device BL'under a guide roll 52 and to and through a tank 53 having a. hot alkaline solution therein. The strip is guided through the tank in a serpentine path by upper and lower rolls 54, 5B, with the result that substantially all of the palm oil on its surface is with to scrub both surfaces of the strip and loosen any traces of palm oil, scale or alkali material still adhering thereto. The loosened material is rinsed oil in a. hot rinse water bath in a tank 62, through which the strip is guided by rolls 63, B4. A plurality of wringers E5, 66, G6 and hot air blowers 61 remove all water from the surface of the strip and effectively dry the same, whereupon it passes through a pair of pinch rolls 68, driven by an electric motor 59, the latter constituting the main drive for unwinding the strip from the unreeling devices 46 or 41 and for drawing the strip through the alkali tank, the scrubber, the rinsing tank and the Wringer rolls.

From the pinch rolls 68, the strip passes to the rst roll of a looper 1U (Fig. 4) or to the first lower roll I5 of the looper Ii (Fig. 1)'. The looper 10 comprises a plurality of lower rolls 1i journalled on a xed lower frame l2 and a plurality of upper rolls 13 journalled on a vertically movable frame 14, supported by cables 15 and an appropriete counterweight, not shown. The strip passes over the several rollers in a serpentine path, to provide a reserve supply of strip between the main supply constituted by the coils 41, 48 and the entrance guide roll 16 of the an nealing furnace, to permit the strip, behind the 1oop'erf1i1 to be stopped while the leading end oi a new reel of steel is Welded to the trailing end of an exhausted reel, while permitting a continuous delivery of strip from the looper to the annealing furnace.

Referring to Figures 2 and 3, when the supply of steel on one of the coils 41, 48, for instance, the latter, is exhausted, and. when the end of the strip has substantially reached the welder 50, the supply of current to the motor 69 which drives the pinch rolls 68 is out off, thereby halting the movement of the line behind the pinch rolls. The leading end of the strip in the coil 41 has previously been,led over a framework 88, including guide rolls 80a, 80h and 80e, substantially into proximity to the Welder 50. The end of this strip is now placed over the rear end of the rst strip in the Welder and a plurality of spot welds or one or more continuous transverse welds are quickly made, to join the strips together. Meanwhile, strip steel is continuously drawn into the furnace from the reserve supply in the looper, and the upper frame 14 is thereby drawn downwardly against the action of its dissolved and removed. A guide roll 5E leads counterweight. As soon as the weld has been completed by thel welder 5D, the motor 69 is started and strip is drawn through pinch rolls 68 at a speed above the normal delivery speed, to replenish the supply in the looper 10, while continuing the delivery of strip to the annealing furnace. Strip is then continuously drawn from the coil 41 at normal running speeds.

A new supply of material, in the form of a new roll or coil, is placed upon a transversely travelling car 8l (Fig. '3) and moved into position immediately in front of the unreeler 46, under the frame 80. The car 8l may be tipped rearwardly, or the coil otherwise rolled onto an elevating platform 82, disposed centrally relative to the coil supporting device 46. By appropriate means, such as an electric motor 83, the elevator 82 is raised, to align the axis of the new coil 48 with the rotatable heads 84 of the coil holder 46. Additional motors operate through appropriate transmission mechanisms to move the rotatable heads 84 and their supporting brackets 4B axially toward or from one another curate alignment of the new coil with the welding machine, guide rolls, tension devices and the like. `This independent adjustment of the coil supporting heads is of considerable importance when coils of varying standard widths are employed.

One or both of the rotatable heads of each reel supporting device is connected through appropriate driving mechanism to an electric motor 86, to`facilitate initialunwinding of the lead- 4ing end of the strip, for attachment to' the trailing en d of the previous strip. This motor, moreover, serves as an electric brake during the normal operation of the apparatus, by simply changing its connections to convert it to function as a dynamo, whereby an accurate control for the tension on the strip is effected.

When the coil 41 is exhausted, the trailing end of the strip thereon is welded to the leading end l of the. new coil 40 and a new roll 41 is mounted in the coil supported 45 by rolling the same along a table 08 onto an elevator 02', similar to the elevator 02 and controlled by an electric motor 00. Since the actuating means for the coil support 45 are substantial duplicates of corresponding elements associated with Vthe unreeling device 46, they will not be described in detail. Thus, strip is continuously delivered tothe annealing oven, first from one roll of metal and then from the other, alternately, and a new roll is positioned in operative relation toits unreeling device while the strip is being delivered from the other-roll.

1 On the discharge side of the furnace, the annealed strip, as it leaves the last cooling chute, travels under a guide roll (Fig. 4) or under the guide roll I4 (Fis. 1) and through positively driven master pinch rolls 0| `(Figs. 5 and 6),

to a rheostat |00, so that, as the coil increases in size, the current delivered through the rheostat to the motor |04 is varied to decrease the speed of the motor. The brake |01, controlled by a suitable foot pedal |00, quickly stops the mandrel and holds it stationary while its supporting shaft is reversed by reversing the motor |04, to contract the mandrel.

Beneath the reeling device |0 I, there' is a transversely movable car |00, mounted on trackways ||0 for movement between a position under the mandrel |02 and a discharge position in alignment with a runway An elevator ||2 carried by the car may be raised to engage and support a completed coil on the mandrel, when the mandrel has been arrested and contracted. 'I'he carr |00 also carries at its innermost end an upwardly projecting stripper block H3, which normally projects behind the end of the coil while the latter is being wound upon the mandrel. Hence, when the car moves outwardly with the coil supported by the elevator, the stripper block ||3 strips the coil cleanly from the mandrel, so that the coil mambe moved to the discharge position. l

Preferably, 'the elevator ||2 comprises three vertically movable supporting blocks which project upwardlyv through appropriate slots in the upper, inclined face ||4 of the car |00. Hence, when the eleva r blocks are lowered at the discharge position, he coil engages the inclined surface ||4 and rolls forwardly therefrom, onto the runway I, where it is held until removal by any suitable means.

The movements of the elevator andthe car are preferably effected by suitable pneumatic cylinders, not shown. which may be controlled by v manually operated vvalves |00' or the like.

which serve to draw the strip through the heating and cooling chambers of the annealing appav ratus, as described in detail below. A looper represented generally at 00 is interposed between the pinch rolls 94, the latter serving to draw the strip through the` looper.- The strip next passes through a looper box 05, a quick-release tension device 06, side guide, centering rolls 01, additional tension devices 00, 00 and over a guide roll |00, which leads the strip to the reeling device |0|,

where the strip is wound upl into the form of a coil on a mandrel |02.

The reeling device |0| includes an expansible and contractible mandrel |02 having an axially extending slot |00 inl its periphery, the parts of the mandrel being so arranged that, when the mandrel is driven forwardly in a clockwise direction by its driving motor |04, the mandrel is in. the expanded position and the slot closed, with the end of the strip firmly clamped therein. When the mandrel is rotated ahead relativel to its supporting shaft or the latter rotated rearwardly relative to the mandrel, while the mandrel is held by the brake |01, the movable parts of the mandrel contract and release the-clamped end During the normal operation ofzhe parts on the delivery side of the annealing apparatus, the pinch rolls 0| are driven continuously at a predetermined speed by a motor 0|', operating through a speed reducer 0|", to draw the strip continuously through the apparatus, for instance, the annealing and cooling .chambers shown in Figures l or 4. A tachometer 0|a may be connected to the motor shaft, to indicate, in feet per minute, the speed of strip travel. The

. llooper 03 is normally `in the lowered position,

substantially as shown in Figure 6 and the pinch l rolls 04 are driven by the motor 04 through speed reducer 04", at the same speed as the rolls 0|. The strip is drawn through the looper box 05, the tension devices and the centering rolls 01 by the reeling device |0| driven by motor |04,

' until a complete coil of metal has been there o! the strip, whereby the coil may be withdrawn l byaxial movement over the free end of the mandrel. The speed of rotation of themandrel is controlled by an arm |05 havin'san end engaging the surface of the coil and .connected 'It wound up. At that time, the motors |04 and 04', driving the reeling device |0| and the pinch rolls 04, are stopped and the strip is cut transversely between the guide roll |00 andthe reeling device Ill. The mandrel is contracted and the coil is removed by the stripperv block H0, elevator ||2 and car |00. The leading end of the strip, behind the line of cut, is clamped in the mandrel |02 and the reeling device is ready to wind up a new coil. Meanwhile, strip steel has been continuoushr delivered by the pinch rlls 0| to the looper 03, and the framework 02 carrying the upper rolls 02' has been rising to accommodate the excess metal thus delivered. As soon as the strip has been started on the mandrel |02, the reeling device |0| and the pinch rolls 04 are set in operation and the excess supply in the looper is gradually diminished. In the event that the looper 00 becomes filled to ca-` pacity before the reeling device lill canf'be restarted, the pinch rolls 34 are, nevertheless, started, to draw the strip through the looper, and the excess material delivered thereby is collected in the looper box, until the reeling device can be operated to handle the strip material in the normal manner. The looper box 35 thus provides a safety factor and accommodates excess strip. since it is of utmost importance that the master pinch rolls 3| operate continuously to draw the strip through the annealing apparatus continuously at a predetermined speed.

The annealing apparatus shown in Figure 4 is generally similar to that described above in connection with Figure 1, but has a greater capacity, since it includes a greater number of heating and cooling chambers and the strip may be drawn therethrough at a somewhat higher rate of speed.

'I'he furnace proper is supported by a suitable framework comprising upright structural members ill, a lower platform ||3, and upper, horizontal frame members ||1. The frame may be braced by suitable tie rods H3, or the like. The platform ||5 supports the furnace casing ||3 made up of a plurality of relatively heavy sheet metal sections continuously welded along their meeting edges and reinforced by suitable angle bars and the like to provide a strong, substantially gas-tight casing structure. Referring to Figures 7, 8, 10, 13 and 14, within the casing ||3 and supported by the platform H5, there is a refractory brickwork hoor |23, and similar side walls |2I, |22, front and back end walls |23 and vertically extending partitions |25, |25 and |25, providing four vertical heating chambers |21,

|23, |23 and |33. The floor |23 is provided with a plurality() of relatively ynarrow openings |21a|33a, registering, respectively, with the vertical furnace chambers. At their upper ends, the chambers terminate in restricted throats lub-|331), respectively, which communicate with roll chambers |3|, |32, lined by continuations of the side and end walls andthe vertical partition |25.

'I'he space between the brickwork walls |2I, |22 and |23 and the metal furnace casing ||3, is packed with suitable heat insulating material, such as rock-wool, asbestos, or the like.

At the lower ends of the vertical chambers 21-133, access doors |33 having' suitably refractory linings |34 are supported for swinging movement to and from closed position by hinge bars |35 (see Figs, 4 and 13).` Hence, the :door of the heating chambers may be inspected and cleaned from time to time.

At its upper end, the furnace casing is offset inwardly at |35 toprovide two independent casing extensions de ng the two roll-receiving chambers l3| and |32. The casing )extensions terminate at their upper ends in two series of flat, horizontally disposed plates |31, providing two rectangular bases (Fig. 16) for rectangular, channel-forming collars |33, one of which is shown in detail on an enlarged scale in Figures 21-24. As shown in Figure 23, each collar com prises an inner angle member |33a, and a vertical, outer plate |33b. continuously welded thereto and braced by triangular pieces |33c, thereby providing a marginal channel |33d which cooperates with a hood, described below, to provide a substantially gas-tight seal for each roll chamber..

As shown in Figures 16, 17 and 19, the upper collar |33 are recessed at |33 to provide spaces for the reception of water-cooled roll shafts hereinafter described. Likewise, the collar |33 (Fig. 22) has an upwardly projecting recess |33', formed by a vertical plate |33e and a semicylindrical plate |38f, providing a rounded hump in the channel I33d, directly above the recess |33, when the parts are assembled.

'I'he roll chambers |3|, |32 are closed by hoods or caps |43, shown more particularly in Figures 12, 25, 26, 27. Each hood comprises side and end walls Ill, a curved top wall |32, suitably reinforced by angle straps |43 carrying lifting eyes' |54', and a refractory brickwork lining |55 for the top and sides. The sides and end walls of each hood carry outwardly and downwardly projecting flanges continuously welded together and to the hood and providing a sealing skirt |45, having a free edge adapted to be received in the channel |33d of the collar |33, as shown in assembled relation in Figures 7 and 8. The end walls of the hoods, at opposite points, are recessed upwardly at |41 to provide a space aligned with the recesses |33, |33', to accommocasing |35 and the horizontal base |31 for the 75 date the water-cooled roll shafts previously mentioned. A semi-cylindrical plate |4141 (Fig. 27) defines the recess and is positioned to embrace the shaft.

Rolls |55, |5| (Figs. 4, 9 and 1l) are fixed to hollow shafts |53', |5|', journalled in outboard bearings |52, |53 carried by the upper, horizontal frame members 1. 'I'he spaces between the shafts and the arcuate recesses |33, |38' and |41 of the roll housing structures are closed by packing glands |52', |53' (Fig. 9), bolted to the exterior face of the casing wall extensions |35 and the collars |33, bolt holes |35a being provided for that purpose (Figs. 19 and 22).

As stated above, the shafts |53', |5| are hollow for the circulation of cooling water through suitable connections at their ends, not shown. As the description of the present invention progresses, it will be apparent that many parts of the apparatus are water-cooled, but ,the cooling water circulating pipes have been omitted from the drawings, since they would only tend to obscure other parts. Y

Below the horizontal platform i6, there is a roll casing, represented generally at |55 in Figures 4 and 14. 'I'he casing comprises a floor member |55a, supported upon transversely disposed I-beamsllt and spaced, longitudinal girders '|55a. Side walls |55b, end walls |55c and a ceiling |55d, provided with suitable openings |55e and a refractory. brickwork lining |51/are supported from the floor |55a. An access door |53, providedy with a suitable refractory lining, is mounted for swinging movement in a manner similar to the door shown in Figure 13, whereby the casing may be inspected and cleaned.

The spaces between the casing walls and the brickwork lining |51 is iilled with insulating materlal |51a. The front end wall |55c is made up of a. plate bolted to the reinforced ,margins of the casing surrounding an opening at that end. The plate may be removed and the insulation at that end broken down, if it is desired to remove the large roll from the interior of the casing for replacement or repair.

Both end walls of the casing |55 are apertured and provided with stumng boxes |53 (Fig. l5), through which the hollow, water-cooled shaft |33 of the lower roll |3| projects, the shaft being iournailed in outboard bearings |32 carried by suitable supporting brackets |33 mounted on the Projecting through a suitable stuillng box |64 Asecured to the end casing plate |65c, is a shaft |65, supported at its opposite end in an appropriate bearing in the opposite end wall, and carrying a scraper blade |66, which projects downwardlyv into contact with the periphery of the roll |6|, to scrape any scale or dirt therefrom, so that a clean roll surface is always presented to the incoming strip of sheet metal. On its outer end, the shaft |65 carries an operating handle |61, whereby the position of the blade |66 and the tension with which it is urged downwardly onto the surface of the roll may be accurately determined. The blade is preferably a resilient, special alloy plate, substantially 11e of an inch in thickness, known inthe trade as resistal #7. l

Beneath the roll casing |55 there are a pair of rolls |69 journalled on appropriate bearings adjacent the opposite ends of the spaced longitudinal girders |56a, whereby, upon occasion, the strip may be led over theroll 18 and under'the outboard bearings |96 (Fig. 9) for a hollow, water-cooled shaft |96', carrying the roll in that housing. The shafts for the rolls in the other roll housings may have bearings |91 associated with the end walls of the housings, since they need not be water-cooled. EachA pair of housings |95, |95a and |95b, |95c is mounted upon an individual base |98, supported on the transverse framemembers ||1b and ||1c.

Certainof the cooling chutes are supported by roll housings 299, 299a, 299|) (Fig. 4), each of which is made up of two sections similar to the casing section |19a of the roll housing |19. The

first casing 299 is .provided with outboard bear? ings 29| for the hollow water-cooled roll shaft, while the other two may have bearings 292 carried directly by the casin'g end walls.

The strip passes under the roll |11 and is drawn upwardly' through a casing section |19a, which, at one side, is bolted, with a suitable gasket interposed,`to the casing |19 and at its upper end |19b is provided with a flange which may be similarly bolted to the lower end of a first cooling chute section |85 (Figs. 4, 30 and 31). Each chute section |85 (Figs. 30 and 31) comprises double-thickness side walls consisting of plates |86, |91 held in spaced relation by short pipe rolls |68, to by-pass the annealing furnace en-Y tirely.

Dispiosecl beneath the platform ||6 andl in substantial alignment with the final heating chamber |39, there is a second roll housing |19, having rolls therein adapted to guide the strip from the final heating chamber to the first cooling chamber. As shown in Figure 14, the housing |19 has an upper 'section |1| communicating through a water-cooled chute section |12 with the opening in the platform ||8 which is aligned with the slit |39a in the furnace floor |29. A roll |13, disposed in the upper section |1|, is fixed to a hollow, water-cooled shaft journalled for rotation in outboard bearings |14 carried by i brackets secured in vertical channels |14' extending between supporting I-beams |82 and the furnace platform. Appropriate stufilng boxes surround the roll shaft to prevent the escape'of gas. The sides of the casing are provided with suitable water-jackets |15, |15a, the latter ofwhich is extended horizontally at |15b over the top wall of the casing proper, The strip is guided under the roll |13 and thence about lower rolls |16, |11, similarly journalled in bearings |18, |19. The bearings |18, like the bearings |14, are supported by the vertical channel |14l while the bearings |19 are carried by `brackets |11. A dirt catching trough |13' extends lengthwise of the casing below the roll |13 and above the roll |16, to prevent Athe entrance of dirt or scale between the strip and the periphery of the latter roll. The

side and end walls of the casing likewise are water-jacketed, as indicated at |89, |8I, to maintain the rolls in reasonably cool relation and to extract heat from the strip passing through the casing. The casing |19 is supported by suitable I-beams |82 or the like.

The cooling section of the apparatus comprises -a vertical frame ,including upright structural sections |88, and rivets |89, or the like, to which 'the`plates are welded, therebyA providing water- :lackets |99, for the circulation of cooling water ,through pipe couplings |9|, |92. Each section is provided with angle iron flanges |93 at its upper and lower ends having appropriate bolt holes therein, whereby lthey may be bolted lto corresponding flanges of the adjacent sections, with 'gas-tight gaskets interposed' between, adjacent flanges, the lowermost ange |93 being bolted to the flange |19b of the casing section |19a (Fig. 14). f

The water-cooled 'chute sections |85 are thus secured together in end to end relation. 'I'he intermediate chute section |85a is further secured to a transverse, horizontal channel member 291 by clips 298 welded to the end walls of the chute and bolted to the channel. In order to provide a space for the channel 291, one of the waterj-ackets |9|ta` is relieved at the upper end, as shown in Figure 32.

'I'he chute sections 293 disposed between the lower roll casing 299 and the upper roll casings |95, |95a` preferably `are constructed substantially in accordance with the showing of Figures 34 and 35. These sections have walls 294 of single thickness, with angle iron reinforcing strips 295, welded thereto, so as to give the sections the required rigidity. 'Ihe sections are bolted tomembers 5a, a pair of upper horizontal I-beams ||,1a, transverse members ||1b, and intermediate transverse members ||1c. The upper frame members |1b and ||1c supports two pairs of casingassemblies, providing fourslmllar roll housings |95, l95a, |961)v and |95c. each of which has 'communication with a pair of vertical chutes.

The met housing las preferably is provided with gether in end to end relation, and to the roll housing, with gaskets between their end flanges 296.

One or more of the sections 293 may be attached` to cross-channels in a manner similar to that shown in Figure 23. The chute sections 298, however, are cooled by exposure to room air alone.

The chutes 2|9, 2| 2|2, 2|3 connected, respectively, to the upper roll housings |a, |95b and |95c and lower roll casings 299a, v299| are made up of sections having means associated therewith for cooling the atmosphere in the chutes and for positively circulating the same over the surfaces lof the strip passing therethrough. A

typical section is shown in Figures 28 and 29,

while the cooling means are shown in Figures 41 and 42.- Each section comprises side plates 2|4, 2|5, reinforced at one end by angle members 2 |6 and cut-away at the opposite end to provide an opening 2|1, defined by marginal flanges all, to 

